Faster playback in VSE
If you want to speed up the overall frames pr. sec. you can do this in the Properties - Output - Frame Rate.
If you just want faster search through the video, two add-ons support this: Power Sequencer(included in Blender, but needs to be enabled in Preferences) or VSEQF: https://github.com/snuq/VSEQF
If you want to only speed up one strip, this can be done by adding a Speed Effect Strip.